If the air-conditioner can be controlled by a Logitech Harmony remote, then you can integrate with smartthings that way.
Or the Remotec ZXT120 is a Z wave device intended for control of IR air conditioners. Itself identifies as a thermostat, but really it’s just a remote for the air-conditioner. There are some community members who are using it.
http://products.z-wavealliance.org/products/715
Vesternet carries it:
http://www.vesternet.com/catalogsearch/result/?q=Remotec+zxt120
Community discussion thread:
Also, anything that has an IFTTT channel/service can be used indirectly with smartthings that way, but the integration may not be as good as the harmony or the Remotec.